Update grafana provider version to 2.8.1

[kunduso]

The changes in this pr closes #43

[infracost]

Infracost report

💰 Monthly cost will not change

Cost details

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6 cloud resources were detected:
∙ 0 were estimated
∙ 3 were free, rerun with --show-skipped to see details
∙ 3 are not supported yet, rerun with --show-skipped to see details

_{This comment will be updated when code changes.}